12 v regulator?

Hello evrybody,

I want to make Wind turbine, by generator car.
How to calculate regulator, from low wind, give the power ?

I quickly read many information that’s ( IEC 61400) :slight_smile:

Add image

I’m not shure that’s Darlington it’s good choise, to you’ve informations ?



Hello Philippe, Welcome to the DigiKey TechForum.
This looks like a nice project that could come in very handy, but I’m not sure how to calculate the information on the regulator. I will let one of the engineers add to this post, as they are more knowledgeable on this subject.

Pardon me. I can’t see a darlington pair in your diagram. In Darlington pair, two collectors of the transistors are shorted. Ref: Introduction to Darlington Transistor - The Engineering Projects I can’t see that here. Measure or estimate the wind speed at the location where the wind turbine will be installed. Wind speed is a critical factor in determining power output.

1 Like


Using an automotive alternator to build a wind turbine for power generation seems like an appealing idea, but it isn’t likely to work well for a variety of reasons. If the regulator circuit shown is used, it’s almost certain to be unsuccessful.

Some reasons that automotive alternators are a bad choice include:

  • Being inefficient: among other reasons, the field winding consumes a substantial amount of power, in the tens to low hundreds of watts, depending on conditions.

  • Being designed for high rotational speeds: an automotive alternator spins at 1000+ RPM under normal conditions, and is designed to generate its usual output voltage at those speeds. In order to get a nominal 12V output at the lower speeds typical of wind turbines, one would need to A) use a pulley system to increase the rotational speed, B) greatly increase the field current, or C) a combination of both. All of these options will cause an increase in already-high loses.

Reasons why the pictured regulator circuit is a poor choice for the stated application include:

  • It drains the battery when the alternator is not spinning, unless a person is willing to sit around and flip the switch depending on wind conditions.

  • It doesn’t allow for maximum power point tracking. In its intended application, an automotive alternator is guaranteed to have more than enough mechanical power available than is needed to generate its electrical output. This will not be the case in any likely wind turbine application. The circuit shown will attempt to increase the field current in order to maintain output voltage at the desired level, and by doing so it will increase the mechanical torque required to spin the alternator. The result will most likely be that instead of charging the battery, the system would end up draining the battery running a magnetic brake that keeps the turbine from spinning in the wind.

All that said, the regulator circuit shown seems workable when there’s more than enough mechanical power available. The output voltage would be set mostly by the Vbe of T1 plus the breakdown voltage of Dz. As the voltage at D+ rises above that value, T1 will turn on, dumping current through R3, causing a reduction in the base-emitter voltage across T2, thereby turning it off and reducing the field current, which eventually ends in a reduction of the voltage at D+.

As a starting point, for a typical 12V automotive application I’d suggest R1=240Ω, R2=100KΩ, R3=1.2KΩ, T1=2N5401, T2=TIP42C, Dz=13v, and D=1N4002. However, there’s little reason to do that when a person can buy a proven solution for probably the same price.

1 Like


One factory make alternator, make from school special hand action, that’s product power …
Me be you don’t understand, more my message …

See you soon